Recently dumped a few PALs from Terminator 2, Mortal Kombat 2 and Operation Thunderbolt.
3 of the Operation Thunderbolt ones are from unsecured devices, the last one wasnt supported by my programmer so is a recreation.
All the Mortal Kombat 2 devices were sent to me by Jon Hughes for dumping, thanks to him for that and to RGP for testing one of them. One of these was a PAL20L8 and have recreated it in both GAL20V8 and GAL22V10 formats.
The last one comes from the sound PCB of Terminator 2. It might yet be the same as the other dump we have from a T-Unit hardware but its a different ID and ive not reversed them both yet to check.
The user ‘frsj8112′ sent in dumps from Hammerin’ Harry (M84 hardware) and Pound for Pound (M85 hardware).The two from Hammerin’ Harry are specific to this game and located on M84-C-B board (the middle one) while The Pound for Pound ones are two on CPU board (the middle one) and one on video board (the top one with scratched off customs).All dumps have been successfully tested on GAL16V8 targeting devices.
Besides, he tested on his Hammerin’ Harry PCB the PALs from our archive ‘m84.zip’ we got from unknown source and found that the one named ‘m84-c-3a_ic8.jed’ is the correct one for this board and it’s unique to this game while the one name ‘m84-a-2h_ic5.jed’ is the same over all the different M84 games.The ones @5L and 7D should be different from game to game.
He also reported feedback on BPROMs.According his tests the bipolar PROM @C37 on M82-B-A VIDEO board can be found also on M84 and M85 hardware although at different location and with different labels.Here’s a reference table fo this BPROM:
After Lifeforce, another awesome Konami shoot ’em up on the bench, it’s the turn of Gradius II – GOFER no Yabou :
Both CPU and video board were in great shape but this is what I got once powered it up:
Board sat down on the above message and very rarely showed an ‘ADDRESS ERROR’ or ‘ILLEGAL INSTRUCTION’ message:
Thanks to my friend Josef who sent me a good Gradius II boardset I could narrow the fault in the CPU board but, before knowing this, during my troubleshooting I found with my logic comparator a couple of faulty Fujitsu TTLs, a 74LS32 @7W on video board and a 74LS157 @8G on CPU board :
So I could concentrate exclusively on CPU board since I know the fault was there for sure.Probing the board with my oscilloscope I found some abnormal activity on a couple of 6264 RAM @10E and 10G :
Launching the game on MAME I could figure out that these two RAMs are used by both the main and slave 68000 CPU :
So a failure in them would explain the missing boot.Not being able to determine which chip was actually faulty, I desoldered both and added sockets:
The one @10G didn’t pass the out-of-circuit test failing in address 1073:
Finally the board could properly boot and enter in game but with missing graphics and crashing after few seconds all the time :
Probing around again with my logic comparator I found a 74LS74 @6F with bad outputs, once removed it failed :
This fixed the board completely, no other issue were present.Evil Konami defeated again.The battle goes on.
Board suffered from a backgrounds issue, screen was filled of blocks of garbage instead of correct tiles.Here a comparison with MAME snapshots.This in the title screen:
This is the in-game :
A video for a better understanding:
The hardware uses the famous ‘GX400’ video board :
The peculiarity of this board is the lack of ROMs, all the graphics is generated by logic of TTLs and custom ASICs.Anyway I has a good starting point since the owner assured me the customs were all good so the problem was TTL related.So I started to check for abnormalities with my logic probe.All was good until I found some 74LS157 with stuck inputs.According schematics they come from a 74LS273 @12B:
As you can see this TTL latches data bits from a 6464 SRAM @15B which is addressed by the custom ‘0005291’ @20D (probably a tilemap generator).Probing it with a logic analyzer confirmed the outputs were all stuck low or high (only one gate was analyzed but all other were confirmed stuck as well with my oscilloscope) :
So confident I removed it (I forgot, obviously it was from Fujitsu):
Once tested out-of-circuit, it failed miserably:
Fitted a rounded machine-tooled socket and a good chip:
And:
Once again Evil Konami has been defeated!See you in the next chapter of this neverending battle…
Another Out Zone PCB (this time on usual ‘TP-018’ hardware) on the bench:
Board was in good shape but I noticed it was heavily reworked on solderside, a lot of ICs were replaced and PCB was not cleaned from solder flux residuals:
Besides, some ground pins of JAMMA edge connector were partially missing or burnt (sign that something gone shorted) and a 100 nF mylar capacitor was missing.I promply restored all of them:
Board booted into game but some sprites were wrong (more than a palette problem it seemed to me an issue related to data bus as if sprites were missing some layers) :
When I went to read the four 1Mbit ROMs containing relevant data I noticed devices were put in wrong sockets:
Silkscreening under the sockets clearly tells where these MASK ROMs must be placed:
But also with ROMs in correct position some sprites were still wrong.I started to test the part of circuit involved in sprites generation and all was fine until I came across two data lines shorted on a 6264 RAM @10A :
The two data lines are connected to the sprites generator custom ‘FCU-2’ and to inputs of a couple of 74LS374 so the short was present also on them.Lifting a pin of the custom didn’t clear the short.
Obviously due the not high resolution of a simple multimeter I could read always a dead short on each of this component.So I decided to use my Polar Toneohm 850A short locator (essentially an audible milliohmmeter) in order to locate the minimum resistance point.
1,110 Ohm measured on the two shorted data lines (pin 12 and 13) of the 6264 RAM @10A:
Around 700 mOhm measured on the two pins of the custom ASIC ‘FCU-2’:
19.3 mOhm on the 74LS374 @19E
17.2 mOhms on the 74SL374 @19C and beep was squeeling at higher frequency :
So I was approaching to the short, it was in the area of the two 74LS374.On part side I didn’t notice anything abnormal so I went to inspect the solder side and after some time I find the culprit:
Two pads connected to inputs of the two 74LS374 were bridged, a ‘kind’ gift of previous repairer.I warmed up my soldering iron and removed it.Powered up the board again :
